Biology: Reproduction Methods

Differences Between Sexual and Asexual Reproduction

• Sexual reproduction involves male and female gametes, resulting in genetically diverse offspring.
• Asexual reproduction produces genetically identical offspring without gametes, utilizing a single organism.

Organisms That Reproduce Sexually or Asexually

• Sexual reproduction organisms include humans, animals, and flowering plants.
• Asexual reproduction organisms consist of bacteria (via binary fission), yeast (budding), and some plants (runners).

Advantages and Disadvantages of Sexual Reproduction

• Advantages: Promotes genetic diversity beneficial for adaptation and survival.
• Disadvantages: Requires more energy and time, and locating a mate can be challenging.

Advantages and Disadvantages of Asexual Reproduction

• Advantages: Efficient and quick, involving only one parent.
• Disadvantages: Results in lack of genetic diversity, more vulnerability to diseases and environmental changes.

Forms of Asexual Reproduction

• Binary Fission: Bacteria split into two.
• Budding: Yeast forms a new organism from the parent.
• Fragmentation: Starfish can develop new individuals from broken pieces.
• Spore Formation: Fungi produce spores that develop into new organisms.
• Vegetative Propagation: Strawberries create new plants from runners.

Difference Between Internal and External Fertilisation

• Internal fertilisation occurs inside the organism's body (e.g., humans, birds).
• External fertilisation happens outside the body, typically in water (e.g., fish, amphibians).

Advantages and Disadvantages of Internal Fertilisation

• Advantages: Higher fertilisation success and embryo protection.
• Disadvantages: Complex mating behaviors and fewer offspring produced.

Advantages and Disadvantages of External Fertilisation

• Advantages: Can generate many offspring without complex reproductive structures.
• Disadvantages: Lower fertilisation success, with many gametes wasted or predated.

Cross Pollination

• Cross pollination involves pollen transfer from one flower’s anther to another’s stigma.
• Advantages: Enhances genetic diversity.
• Disadvantages: Relies on pollinators or environmental factors, with higher failure rates.

Ways Cross Pollination Occurs

• Mechanisms include wind, insects (e.g., bees, butterflies), birds, and water.

Self Pollination

• Self pollination occurs when pollen transfers from the anther to the stigma of the same or another flower on the same plant.
• Advantages: No external pollinators needed and provides consistency.
• Disadvantages: Reduces genetic diversity, limiting adaptability.

Male and Female Sex Cells of a Flower

• Male sex cell: Pollen produced in the anther.
• Female sex cell: Ovule contained within the ovary.

Function of Each Reproductive Component of a Flower

• Stamen (male part): Anther (produces pollen) and filament (supports anther).
• Pistil (female part): Stigma (receives pollen), style (connects stigma to ovary), ovary (contains ovules).
• Petals serve to attract pollinators; sepals protect the flower bud.

Process of Pollination and Fertilisation in a Flower

• Pollination involves transferring pollen from anther to stigma.
• Fertilisation occurs when a pollen tube grows from the stigma to the ovary, fertilizing ovules and forming seeds.

Male and Female Gametes in Humans

• Female gamete: Egg (ovum).
• Male gamete: Sperm.

Male and Female Gonads

• Male gonads: Testes.
• Female gonads: Ovaries.

Function of Structures in the Male Reproductive System

• Penis delivers sperm into the female reproductive system.
• Urethra carries both urine and semen out of the body.
• Testicles produce sperm and testosterone; scrotum protects testes.
• Vas deferens transports sperm from the epididymis.
• Epididymis stores and matures sperm.
• Prostate gland produces nourishing fluid for sperm.
• Seminal vesicle generates a sugar-rich fluid providing sperm energy.

Purpose of Semen

• Semen functions to transport and nourish sperm during ejaculation.

Structures Involved in Making Semen

• Key structures include testes, prostate gland, seminal vesicles, and bulbourethral glands.

Hormone Produced by the Male Gonad

• Male gonads produce testosterone.

Function of Structures in the Female Reproductive System

• Ovaries produce eggs and hormones, including estrogen and progesterone.
• Fallopian tubes transport eggs from the ovaries to the uterus, where fertilisation typically occurs.

Explore the key differences between sexual and asexual reproduction in this quiz. Understand how various organisms utilize these methods to perpetuate their species, focusing on genetic diversity and reproduction processes.